Man, just... please, stop deceiving people.
Your theory that the game being a harem is mandatory to be popular and profitable is just a big lie.
Plenty of games there that are very popular are not harems, in fact majority of the most popular games are not harems.
We can also argue of course about the definition of "popular" but common.
Your wishful thinking is a one thing. reality - another.
As it was said - variety is great, not every game should be harem, again, majority of games here are harems, don't you have enough that you jump into every non-harem thread and start this "I want harem" debates? I am not referring to you exactly of course but in general.
Fantasy or not, there are some immersive players here who enjoy good story and believable characters, some are looking for romance. Personally for me it's hard to take the story and girls seriously in harem games when you simply fuck everything that moves throughout the game and just collect them at the end aka pokemons and make orgies. Maybe that's because I never actually saw pokemons series who knows.
Personally I can accept harem route in a dystopian or fantasy setting when the story is build in way that somehow justifies it without MC acting like man-whore, but that's it, even in this case harem-route would the last one in priority for me.
There are exceptions of course but not that many.